Heat dissipation device with convection driven impeller

ABSTRACT

An exemplary heat dissipation device includes a base, spaced fins, a bracket, a shaft and a first impeller. The base directly contacts a heat-generating source. The fins are mounted on the base to dissipate heat transferred from the base by nature convection and thermal radiation. The bracket is mounted on the fins and includes a rotor. The shaft is engaged with the rotor and is located above of the fins. The first impeller is located at above of the bracket and engaged with a top end of the shaft. Heat generated by the heat-generating source is absorbed by the base and then is transferred to the fins for dissipation. Air around the fins and the base is heated and moves upwards to drive the first impeller to rotate.

BACKGROUND

1. Field of the Invention

The present disclosure relates to heat dissipation devices typically used in electronic devices, and more particularly to a heat dissipation device for dissipating heat generated by electronic components of an electronic device.

2. Description of Related Art

As electronic products continue to develop, heat generated from electronic components of the electronic products has increased correspondingly. Conventionally, a heat absorbing member is used to contact an electronic component of an electronic product to absorb heat generated from the electronic component. However, typically, the heat of the heat absorbing member is dissipated slowly via natural convection and thermal radiation in a narrow space inside the electronic product. Therefore, the electronic component is still prone to become overheated.

What is needed is a heat dissipation device which can overcome the above-described problems.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an assembled view of a heat dissipation device of an exemplary embodiment of the present disclosure.

FIG. 2 is an exploded view of the heat dissipation device of FIG. 1.

FIG. 3 is an inverted view of the heat dissipation device of FIG. 2, and showing an electronic component in contact with a base of the heat dissipation device.

DETAILED DESCRIPTION

Referring to FIGS. 1-2, a heat dissipation device 100 of an exemplary embodiment of the disclosure includes a base 10, a fin group 20 arranged on the base 10, a bracket 30 mounted on the fin group 20, a first impeller 50 located above the bracket 30, a second impeller 60 enclosed by the fin group 20, and a shaft 40 rotatably engaged with the bracket 30 and interconnecting the first impeller 50 and the second impeller 60.

Referring also to FIG. 3, the base 10 is a disk-like sheet and has good heat absorbing capability. The base 10 includes a top surface 11 and a bottom surface 12. The bottom surface 12 directly contacts an electronic component 70 to absorb heat generated therefrom.

The fin group 20 includes a plurality of fins 21. The fins 21 are radially mounted on the top surface 11 of the base 10, and are evenly spaced from each other along a circumferential direction of the base 10. Each fin 21 is an elongated plate. A width of each fin 21 is generally increased from a top end thereof away from the base 10 to a bottom end thereof mounted on the base 10. Each two adjacent fins 21 cooperatively define an air passage 22 therebetween. Outer edges of the fins 21 are located inwardly from a periphery of the base 10. Inner edges of the fins 21 are spaced from each other and cooperatively define a receiving chamber 23 therebetween. An inner diameter of the receiving chamber 23 is decreased from top to bottom.

The bracket 30 includes a connecting portion 31, an engaging portion 32, a rotor 34, and a plurality of ribs 33. The connecting portion 31 is an annulus, and an outer diameter of the connecting portion 31 is larger than an inner diameter of a top end of the receiving chamber 23. The engaging portion 32 is an annulus, and is located at a center of the connecting portion 31. The rotor 34 is received in the engaging portion 32, and is rotatable relative to the engaging portion 32. Each rib 33 is an elongated strip. The ribs 33 are evenly angularly spaced from each other, and are located between and interconnect the connecting portion 31 and the engaging portion 32.

The shaft 40 is an elongated cylinder and extends through the rotor 34. A central portion of the shaft 40 is engaged with the rotor 34. Opposite ends of the shaft 40 are located beyond the bracket 30 and are located at opposite top and bottom sides of the bracket 30. The rotor 34 rotates in unison with rotation of the shaft 40.

The first impeller 50 is a centrifugal impeller, and is made of lightweight material. The first impeller 50 includes a hub 51, and a plurality of blades 53 radially extending from an outer periphery of the hub 51. Each blade 53 is an elongated sheet with an arc-shaped transverse cross-section. A width of the blade 53 is increased from an inner end connecting the hub 51 to an outer end away from the hub 53. The blades 53 extend outwardly and slantwise from the hub 51 and are equally angularly spaced from each other. In addition, the blades 53 can be considered to successively extend along an anti-clockwise direction of the first impeller 50. A diameter of the first impeller 50 as defined by the blades 53 thereof is larger than the outer diameter of the connecting portion 31 of the bracket 30.

The second impeller 60 is a centrifugal impeller, and is made of lightweight material. The second impeller 60 includes a hub 61, and a plurality of blades 63 radially extending from an outer periphery of the hub 61. Each blade 63 is a vertical, rectangular sheet. A diameter of the second impeller 60 as defined by the blades 63 thereof is smaller than the diameter of the first impeller 50.

In assembly of the heat dissipation device 100, the central portion of the shaft 40 is engaged with the rotor 34, with the rotor 34 being rotatably engaged in the engaging portion 32 of the bracket 30. The opposite ends of the shaft 40 are inserted into the hubs 51, 61 of the first and second impellers 50, 60. Thereby, the first and second impellers 50, 60, the shaft 40 and the bracket 30 are assembled together. A distance between a bottom surface of the connecting portion 31 of the bracket 30 and a bottom end of the second impeller 60 is smaller than a depth of the receiving chamber 23. The second impeller 60 is inserted in the receiving chamber 23 from the top end of the receiving chamber 23. The bottom surface of the connecting portion 31 abuts against inner portions of top ends of the fins 21. The first impeller 50 is located above the fin group 20. In this state, the second impeller 60 is located at a bottom of the receiving chamber 23 and spaced from the top surface 11 of the base 10 and the inner edges of the fins 21.

In use of the heat dissipation device 100, when the electronic component 70 is working, heat generated by the electronic component 70 is absorbed by the base 10 and then is transferred to the fins 21 to radiate from the fins 21. Air around the base 10 and the fins 21 is heated by the base 10 and the fins 21 and moves upwards. The moving heated air drives the first impeller 50 to rotate. The second impeller 60 rotates in unison with the first impeller 50 to agitate air in the receiving chamber 23 to make such air flow from the receiving chamber 23 through the air passages 22 between the fins 21. In addition, the first impeller 50 itself agitates air around the heat dissipation device 100. The first impeller 50 and the second impeller 60 thus increase the heat radiation efficiency of the fin group 20.

Alternatively, in other embodiments, the second impeller 60 can be omitted, such that the heat dissipation device 100 only includes the first impeller 50. In such embodiments, the moving heated air drives the first impeller 50 to rotate. The first impeller 50 agitates air around the heat dissipation device 100 to increase the heat radiation efficiency of the fin group 20.

It is to be understood, however, that even though numerous characteristics and advantages of the embodiments have been set forth in the foregoing description, together with details of the structures and functions of the embodiments, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the disclosure to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed. 

What is claimed is:
 1. A heat dissipation device for dissipating heat generating from a heat-generating electronic component, the heat dissipation device comprising: a base for directly contacting the heat-generating electronic component; a plurality of spaced fins radially mounted on the base to dissipate heat transferred from the base by convection and thermal radiation, the fins cooperatively defining a receiving chamber between inner edges thereof; a bracket mounted on the fins and comprising a rotor; a shaft extending through and engaged with the rotor, top and bottom ends of the shaft located at opposite top and bottom sides of the bracket; a first impeller located above the bracket and engaged with the top end of shaft; and a second impeller received in the receiving chamber of the fins and engaged with the bottom end of the shaft; wherein heat generated by the heat-generating electronic component is absorbed by the base and then is transferred to the fins for dissipation, air around the fins and the base is heated and moves upwards to drive the first impeller to rotate, and the second impeller rotates in unison with the first impeller to agitate air in the receiving chamber.
 2. The heat dissipation device as in claim 1, wherein each fin is an elongated plate, and a width of each fin is generally increased from a top end thereof away from the base to a bottom end thereof mounted on the base.
 3. The heat dissipation device as in claim 2, wherein the fins are evenly angularly spaced from each other, and each two adjacent fins cooperatively define an air passage therebetween.
 4. The heat dissipation device as in claim 2, wherein the base is a disk-like sheet, and the fins are mounted on a top surface of the base.
 5. The heat dissipation device as in claim 4, wherein outer edges of the fins are located inwardly from a periphery of the base.
 6. The heat dissipation device as in claim 1, wherein the bracket further comprises a connecting portion abutting against top ends of the fins, an engaging portion enclosed by the connecting portion, and a plurality of ribs located between the connecting portion and the engaging portion and interconnecting the connecting portion and the engaging portion, and the rotor is received in the engaging portion and rotatable relative to the engaging portion.
 7. The heat dissipation device as in claim 1, wherein each of the first impeller and the second impeller is a centrifugal impeller made of lightweight material.
 8. The heat dissipation device as in claim 7, wherein the first impeller comprises a hub and a plurality of blades radially extending from an outer periphery of the hub, and the blades extend outwardly and slantwise from the hub and are equally angularly spaced from each other.
 9. The heat dissipation device as in claim 8, wherein each blade is an elongated sheet with an arc-shaped transverse cross-section, and a width of each blade is increased from an inner end connecting the hub to an outer end away from the hub.
 10. The heat dissipation device as in claim 7, wherein the second impeller comprises a hub and a plurality of blades radially extending from an outer periphery of the hub, and each blade is a vertical, rectangular sheet.
 11. The heat dissipation device as in claim 10, wherein a diameter of the first impeller as defined by the blades thereof is larger than a diameter of the second impeller as defined by the blades thereof.
 12. A heat dissipation device for dissipating heat generating from a heat-generating source, the heat dissipation device comprising: a base for directly contacting the heat-generating source; a plurality of spaced fins mounted on the base to dissipate heat transferred from the base by convection and thermal radiation; a bracket mounted on the fins and comprising a rotor; a shaft engaged with the rotor and located above the fins; and a first impeller located above the bracket and engaged with a top end of the shaft; wherein heat generated by the heat-generating source is absorbed by the base and then is transferred to the fins for dissipation, and air around the fins and the base is heated and moves upwards to drive the first impeller to rotate.
 13. The heat dissipation device as in claim 12, wherein the first impeller comprises a hub and a plurality of blades radially extending from an outer periphery of the hub, and the blades extend outwardly and slantwise from the hub and are equally angularly spaced from each other.
 14. The heat dissipation device as in claim 13, wherein each blade is an elongated sheet with an arc-shaped cross-section and a width of each blade is increased from an inner end connecting the hub to an outer end away from the hub.
 15. The heat dissipation device as in claim 12, further comprising a second impeller enclosed by the fins, the shaft extending through the rotor and engaging with the second impeller, and the second impeller rotates in unison with the first impeller.
 16. The heat dissipation device as in claim 15, wherein the second impeller comprises a hub and a plurality of blades radially extending from an outer periphery of the hub, and each blade is a vertical, rectangular sheet.
 17. The heat dissipation device as in claim 12, wherein each fin is an elongated plate, and a width of each fin is generally increased from a top end thereof away from the base to a bottom end thereof mounted on the base.
 18. The heat dissipation device as in claim 17, wherein the base is a disk-like sheet and the fins are radially mounted on a top surface of the base, and evenly spaced from each other along a circumferential direction of the base.
 19. The heat dissipation device as in claim 17, wherein inner edges of the fins cooperatively define a receiving chamber therebetween, and an inner diameter of the receiving chamber is decreased from top to bottom.
 20. The heat dissipation device as in claim 12, wherein the bracket comprises a connecting portion abutting against top ends of the fins, an engaging portion enclosed by the connecting portion, a plurality of ribs located between the connecting portion and the engaging portion and interconnecting the connecting portion and the engaging portion, and the rotor received in the engaging portion and rotatable relative to the engaging portion. 